Electric floor-push



(No Model.)

H. G. THOMSON.

ELECTRIC FLOOR PUSH. v

Patented Dec. 22, 1896..

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norms PETERS ma-rnum UNITED STATES PATENT OFFICE.

IIEXRY O. THOMSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE ELECTRIC GAS LIGHTING COMPANY, OF MAINE.

ELECTRIC FLOOR-PUSH.

SPECIFICATION forming part of Letters Patent No. 573,723, dated December 22, 1896.

Application filed March 28, 1896- To all whom it may concern:

Be it known that I, HENRY C. THOMSON, of Boston, State of Massachusetts, have invented a new and useful Electric Floor-Push, of which the following is a specification.

My invention relates to that class of electric press-buttons which are frequently used in connection with the dining-table or in similar places. In this class of apparatus the following construction is well known. A metal plate is screwed to a plug of insulating material, to which are fixed two circuit-springs which bend toward, but do not touch, each other below the plug, to which springs the circuit wires are attached-for instance, beneath the floor in a dining-room. In the hollow center of the plug is concealed a small coiled spring. A pin or shank, having a shoulder below its head, passes into this hollow center. Its shoulder restsnormally upon the coiled spring, and when the foot is placed upon the head of the pin or shank and pressure exerted the spring is depressed and the lower part of the pin passes between the two contact-springs, completing the electric circuit, which runs to a bell or other form of annunciator in a well-known fashion.

In connection with the above-described apparatus it has been usual to provide an ancillary device by which the two circuitsprings upon the plug might be connected with a press-button upon the dining-table by means of a flexible cord carrying two electric wires, so that the press-button at the table can there complete-the circuit instead of completing it by the pin pressed upon by the foot, as above described. Such devices have been composed of a piece of insulating material carrying two contact-prongs which pass through perforations in the metal plate and insulated plug embedded in the floor of the room, and so make contact with the two contact-springs above mentioned. This construction is open to two very decided objections. In the first place it requires a threefold perforation of the carpet or rug. In the second place this construction so projects above the floor as to be inconvenient and also likely to be broken in the movement of furniture. It is also necessary frequently to remove both the connection with the table and Serial ITO-585,154. (No model.)

also the foot-pin in cases where a smooth floor is desired for any reason.

My invention consists in a different construction of the apparatus to be operated from the table, whereby I not only avoid the two extra perforations of rugs or carpets, but I also obtain a smooth convex projection at the floor when it is desired to have the pushbuttonat the table.

My invention will be more easily understood by reference to the drawings, in which- Figure 1 is a vertical section. Fig. 2 is a horizontal section on the top of plate A. Fig. 3 shows the ordinary pin when the apparatus is to be operated by the foot.

I will now describe my invention in connection with the drawings.

A is the plate, having two screw-apertures o' i; B, a plug of insulating fiber screwed to said plate and recessed at b.

O O are two contact-springs, 0 being longer than C for reasons which will presently be explained, both contact-springs being prop- I erly riveted to the plug B and connecting with the circuit-wires g g.

D is a metallic pin or shank, hollow in its center, having the screw-threaded head (Z, upon which is a piece of insulating material d. The pin D has the shoulder d and above the shoulder two pins (Z which pass through the plate A at m, while near its lower extremity D is inserted a small piece of insulator (1 containing a steel pin it, holding D and D together, but insulated by C1 The flexible cord E carries the two electric-circuit wires e e, which join with two of the screws (2 e the latter, e being insulated from the top cl.

F is a metallic plate having a convex upper surface and a chamber f, whose sides are threaded to enable F to screw onto the head d. F is perforated to admit the passage of the flexible cord E, and there is preferably an insulating-ring. (not shown) through which said cord runs. The electric-circuit wire 6, which connects with the insulated screw 6 continues thence down the center of the rod D,incased in insulating-cord k,until it reaches and makes contact with the steel pin it.

' n is a helical spring normally holding the pin D in the position shown in Fig. 1, and 0 ICO is a washer between the spring and the shoulder (1 The operation of the apparatus will be easily understood. If, for instance, nothing is required but an ordinary floor-push, the shank D D will be withdrawn from the plate A and plug B and the shank F D substituted, the well-known operation of which will be as follows: Its shoulder 61 will rest, as would the shoulder (Z of the shank D, upon the washer 0. The shank itself will be in constant contact with the circuit-spring C, but not normally in contact with the circuit-spring G. Then, however, the foot is placed upon the head F and the shank depressed against the force of the spring 72, its lower extremity will come in contact with the circuit-spring C,thus completing the electric circuit to the battery for ringing the bell or operating the given annunciator.

Speaking generally, the apparatus, when thus constructed and operating, is quite similar to well-known apparatus for this purpose, except that both circuit-springs are usually of equal length and the pin is normally out of contact with both; but when it is desired to operate by means of a press-button attached to, for instance, the under side of the diningtable, desk, &c., the construction and position of the parts under my invention will be as shown in Fig. 1. There will be but one perforation through the carpet, and that may be by an eyelet,avoidingin jury of the threads. The carpet will cover the plate A, partially filling the space between it and the cap F. By means of the two pins (1 the space between A and d may be more or less, according to the thickness of the carpet.

There may be, although not shown in the drawings, a slight notch or notches on the under side of A, in which either of the pins (Z may catch to avoid disturbing the cap F in sweeping, &c. From the push-button at the table run the two circuit-wires e 6 through the cord E, diverging from each other in the chamber f. The wire a, being insulated, runs down the cord k in the center of the pin D and makes electrical contact with the steel pin 71., which is in electrical contact with the part I), whence the circuit continues through the spring 0 to the circuit-wire g. The wire 0 makes electrical contact with d, thereby be ing in electric circuit with the shank D, the spring 0, and so to the circuit-wire g. hen

the circuit is connected at the table by means of the push-button, the bell or annunciator is made to operate. By my invention, therefore, I secure a permanent part of an electric push, which is capable of being used either -with the ordinary floor-push F D or with my 1. For an electrical floor-push, the combination of the plate A, insulated plug B attached thereto, the helical spring '12, the circuit-spring O, and the circuit-spring O, which is longer than C, and a circuit-closing pin; all substantially as and for the purposes described.

2. For an electric floorpush, the combination of the perforated cap F threaded as shown and having the chamber f, the hollow shank-pin D having the top (Z and the insulating-piece cl, and one or more pins (1 the insulating-piece d, the lower extremity D, and the metallic pin it connecting the parts D D, substantially as and for the purposes described.

3. For an electric floor-push, the combination of the perforated cap F threaded as shown and having the chamber f, the hollow shank-pin D having the top d and the insulating-piece d, one or more pins (Z the insulating-piece (1*, the lower extremity D, and the metallic pin h connecting the parts D D, and the plate A, the insulating-plug B, the spring 11, the circuit-springs O O and the circuit-wires e 6, arranged as described, all substantially as and for the purposes described.

4. In an electric floor-push, the combination of a perforated cap, a connected, headed, hollow shank having its extremities insulated from each other, a pin physicallybut not electrically connecting the upper and lower por tions of said shank, a sustaining-plate, and a plug attached thereto, and propercircuit connections therefor, substantially as shown.

In witness whereof I have hereunto set my hand, in the presence of two witnesses, this 25th day of March, A. D. 1896.

HENRY O. THOMSON. lVitnesses:

STEPHEN A. FOSTER, WILLIAM M. PAYsoN. 

